Arrangement in digesters adapted for manufacturing cellulose and working with circulation effected by a centrifugal pump



Aprll 18, 1933. Q w E 1,904,810

ARRANGEMENT IN DIGESTERS ADAPTED FOR MANUFACTURING CELLULOSE AND WORKING WITH CIRCULATION EFFECTED BY A CENTRIFUGAL PUMP Filed May 7, 1932 3 Sheets-Sheet l 0- /-7- Wren April 18, 1933. Q w E 1,904,810

ARRANGEMENT IN DIGESTERS ADAPTED FOR MANUFACTURING CELLULOSE AND WORKING WITH CIRCULATION EFFECTED BY A CENTRIFUGAL PUMP 3. Sheets-Sheet 2 Filed May '7, 1952 y ,2 Mr? Aprll 18, 1933. Q W E 1,904,810

ARRANGEMENT IN DIGESTERS ADAPTED FOR MANUFACTURING CELLULOSE AND WORKING WITH CIRCULATION EFFECTED BY A CENTRIFUGAL PUMP Filed May 7, 1932 3 Sheets-Sheet 5 me n Pa'tented Apr. 18, 1933 os'olm ALBANUS wmnn, or smooxn'onm, SWEDE V f analizenunnr lin nI EstrEas nimrrn n iron mauuracruni ne oELLnLosn wonxnvewrr'n omcULATroN nrrncrnnznyn oENTmFUGA 'rUi/rr ma a med Maj7,1932, Serial nojeoa'eie, andiniSwed'en jui 2e, 1930. f-

' i The present {invention relates to an improvement in 'diges'ters adapted for 'manufacturing cellulose and working with-circulation'of liquor effectedby a centrifugal puinpJ-fIThe ,objectof the invention is essentially to facilitate the circulation of liquor by reducing the hydraulic losses as far as possible so as to allow the speed of the circulating liquor to be increased and, thus, the

out the necessity of overdimensioningthe apparatus of circulation.

According to the invention this is, in the first place, realized by the fact that the sys-,

tem of circulation is provided with a centrifugal pump having one or morevspiralshaped suction chambers arranged sov asto permit the liquor, before entering into the impeller, to receive a tangential component. of velocity. Thus, the liquor will be intro-. pump evenly distributed andnected with the pump by means of a branch pipe having a number of branches corresponding to the number of the suction pipes. At the junction or branch point said branch pipe has its branches arranged in parallel or essentially in parallel and the total crosssection of the difierent branches, immediately before the junction-point, is substanpipe after the junction-point so as to permit the different currents to or whirling.

Otherv features characteristic of the in- 1 vention will bemore closely set forth in the if'ollowing inconnection with the circulationto be made more eflicient with-' respectively inaFig.'-5.':

tending from the latter and running: within tion pipes are-:joi'ned together immediate;-

the suction pipes (two or morelare contially equal with thecross-section of the join without impact a tion of thejembodiment illustrated in the annexed drawings? 1- Referring to the. drawings, Figs. land-,2

showthe plantas a'whole, intwo different r 3 sideviews. Figs. {land 4"show-the centrif;

ugal pump from two .diflferent'sides, partly in section. Fig; 5. shows'an embodimentlof; I the multiple; branch pipe in longitudinal section, and Figs. 6, 7 and .8 are: sections on @5 lines VI'VI, VIIIVII andgVIIlf'eVIII In F gs. 1 and 2, 'vided with the sieve 2 and two pipes 3 ex 1 V. the dlgester. Eachofsmd; p1pes3 -1s, at

the point inwhichit, leaves the;, digesterj,

connected to a valve 4 provided with ,two outletsi uConnected to these: g joutletsw fare two suction", pipes 57 and 6. Theseii sue;

ly before the inlet 8 of the centrifugal-pump 7 "by a multiple branch pipe 9,, thejd'esignpf which being more sclosely ,set' forth in the followingi From the pump the liquor (lye) 5 is forced up throughwa heating-device.110, which is, for instance,- heated by means; of

vapor-introduced through the pipe 11 and f removed through the pipe 12. Condensed water is drawn oil" through the pipe 13; to the-steam trap 14; From the heating-device the he'ated'liquor will .then bercarriedofl'to the upper part of tho digester through: the pipes15,-which may'ibe drawn in any-suit:- ablemanneru' a f a,

In order to'obtain a circulation as-strong v as possible, according (tothes inventiOn,-' the.

centrifugalpump isprovided withoneflior t more tangential inletswzgv- Figs, 3 and 4 show a tangential inleticham r 6 nel 16 at each side-of thepumpl There is, howeverl,--nothing (preventing theuse' lofxa pump having one'or: more tangential inlets at one side only, also several-tangential in:

By means of the tangential" inlet/or inlets a particularly good "distribution Oifirvljllfi liquor around the entire entrance" 18 of the impeller '17; isfobtainedf'and whirlings" and impacts ware avoided, which would reduce 1 .00

I embodiment of the multiple branch pipe or Y-branch 9 joining two branch pipes 20 and 21 to a common pipe 22. As shown in Fig. the two branches and 21 are parallel at the point of'joining with the pipe 22. The

1G cross-sections of the branch-pipes form together a section substantially equal to the cross-section of the pipe 22 immediately after the junction-point, compare Figs. 7

- and 8. By suchv a multiple branch pipe the different currents of liquor will be brought together without impact if the velocity of flowing of the liquors, at least at the junction-point of the branches, is equal in all branches. The different ends of the multiple branch-pipe have preferably a circular cross-section in order to enable the connection of the multiple branch pipe to circular pipes or connecting branches.

Finally, it should be pointed out that, of course, a multiple branch pipe according to the present inventionoffers the same advantages when a main current is' to be divided into a number of branch currents as when the contrary course takes place. 7 Having now particularly described the naturefof my invention and the manner of its-operation, what Iclaim is:

1. Improvement in circulating systems for cellulose 'digesters wherein the reaction liquid by means of a pump aggregate is forced to circulate through the digester and .an outside pipesystem, consisting in the arrangement of a'plurality of suction pipes conveymg reaction liquid from the digester to an intake of a pump; a'multiple-branch unit provided with a plurality of inlet branches and a common outlet uniting said suction pipes with said intake; the inlet channels of said'multiple-branch unit being at the plane of junction paralleljwith each other and with the outlet channel, and adjacent channels separated by means of edged partitions; said immediately after said plane of junction.

will enclose areas with coincident interior ;outlines, so that the inlet channels will smoothly merge without any projections and obstructions into the outl'et'channel.

3. The improvement in circulating systems for cellulose digesters as set forthin claim 1, and in combination with centrifugal pump-s provided with spiral-shapedsuction chambers. Y 7 f In testimony whereof I aflix my signature.

' OSCAR ALBANU'S WIREN. 9

channels being so formed that cross-sections taken immediately before and immediately after said plane of junction will. enclose areas w1th coincident interior outlines, so

that the inlet channels will smoothly merge without any projections and obstructions into the outlet channel.-

2. Improvement in circulating systems for cellulose digesters wherein the reaction liquid by means of a pump aggregate is forced to circulate through the digester and an outside pipe system, consisting in the arrangementof a plurality of groups of suction multiple-branch unit provided with a pluralityiof inlet branches and a common outlet 

